Hello again We just got this grader and it has this code on screen. As I understand is engine coolant fan solenoid current below normal. In this case I need to look for a cut wire. Operator mentions that when machine is warm and climbing engine losses some power. Could this code be related to this problem?
One of the results of this code is that the ECM cannot control fan speed therefore the engine can overheat and lose power. I've sent you the Diagnostic Procedure.
I was looking the electrical diagram and it shows 148-2350 as part number. But if I go to parts manual it shows 183-7595. Plus I can´t find it. There`re like 4 items with the nº 31 in electrical diagram
The Electrical Schematic was last updated in 2005. The Parts Book dates from January 2013. My system shows that the 148-2350 Coil Assembly is actually a part of the 183-7595 Solenoid Valve Group. The latest Part Number of coil in the 183-7595 assembly since Sept 2011 is 312-8629. Just check your valve assembly and make sure the coil can actually be removed from it before ordering.
Sorry, forgot to address your issue of not being able to find it. The 191-5292 Manifold that contains the valve which controls fan speed is part of the 175-6978 Hydraulic Fan Lines Group. The manifold is located underneath the operator's cab.
ok, If I`m not wrong this is the assembly And this is the solenoid The fan starts right away, even with the solenoid plugged and unplugged. I measured resistance and it was 4.8 ohms. Nige, the ECM related for the test is the one at the engine right?, cuz the one below cabin is for the transmission. Also, do you know the work pressure? I saw a port in the assembly and I thought about measuring the hydr pressure for the fan.
That's the valve. It's controlled by the engine ECM. The specification I have for it are 1160 +/- 75psi. However according to the T&A the important thing is fan speed - 1210+/-25 RPM, system pressure is for reference only. To make the test you have to have the fan running at 100% speed, either by using ET or somehow fooling the engine ECM that full fan speed is desired. Rig the engine coolant temp sensor maybe..?
Can I plug 24v to the solenoid and see how it works?
I don't think so. There is a pressure sensor for the hydraulic fan that sends a signal to the ECM (plus I guess an input from the engine coolant temperature sensor) then the ECM sends a signal to the solenoid. All feeds, returns, signal, & grounds, come and go to/from the ECM and all sorts of weird & wonderful things go on in those Black Boxes I can tell you. Have you measured the input voltage at the solenoid from the ECM when the engine is running to see what it is..? After measuring that measure the voltage across wires H746 Yellow & H747 Brown (pins 43 & 51 of connector J1 on the ECM) to see if the 2 readings are the same. You could have a wire break in the harness between the ECM and the solenoid. BTW your solenoid resistance should be 5.0 ohms+/-0.3, so at 4.8 you are OK on the coil.
I measured the voltage at the solenoid and it reads 26v. Also I plugged 24v to the solenoid (sorry I did it before reading last reply). Any way, inside it moves like 2mm. I was thinking in borrowing another solenoid and tº sensor from the 140M but dont know if they´re same type
IIRC Your 140M is an early B9D prefix. The 2 valves for the demand fan are notthe same Part Number however they are the same solenoid (148-2350 CRB 312-8629) and same valve cartridge (154-4133 CRB 316-1438). What's different is the adapter where the complete valve assembly screws into the manifold. Your 140H is Part # 184-3409, the 140M is Part # 189-8624. If you can get past that problem your 140Mvalve will work in your 140H. However I don't think the valve is the problem, I think it's either the "signal" from the ECM of it's hydraulic and likely fan pump/motor related.
I just found out that 2 years ago the motor shaft broke down. It was welded and has been working. But the code showed up couple of weeks ago
I bet your mind is working in a totally different direction now, right ...?
Since I dont have ET I will measure work pressure for the fan. BTW, I was looking the 140M fan and when starts, it starts slowly. The other one starts fast right away
Pump control valve or pump..?
The fan. At the 140M starts slow (normal to me) then warm starts faster. The 140H starts fasts. I measured the signal at the ECM and it is 26volts, at solenoid is 26volts also. Code is still active. It is possible the pump (at the fan) is not working properly and generate that code? But if the fan is working fast is because of the hydr oil.
Here's the Systems Operation details of the fan pump from the service manual................. Piston Pump (Hydraulic Fan) The piston pump for the hydraulic fan is a variable displacement axial piston pump. The piston pump for the hydraulic fan is used to supply oil to the fan motor. The piston pump for the hydraulic fan contains a pressure and flow compensator valve. The pressure and flow compensator valve regulates the fan circuit. If the fan starts fast right from the start when the engine is cold then I suggest you need to be looking at the pressure & flow compensator valve, that's what telling the pump to deliver the amount of oil to the fan motor that it is actually delivering.
I made the pressure test. I unplugged the connector from the solenoid and it reads 600psi. Also with the connector plugged the pressure is the same. In both cases, when starting engine, pressure reaches 1000psi for like 2 secs, then drops to the 600psi and keeps like that. I unplugged the engine tº sensor and result is the same, 600psi. Could it be ht solenoid resistance is fine, but the spool got stuck?
Sorry I was wrong saying the fan starts fast. It just keep same speed always. I thought that was the max speed.
Got a question. If I unplugged the connector from ECM to solenoid (no signal to fan solenoid) The fan should get max speed right? I mean ECM doesnt know if solenoid is working so to avoid overheating, the fan has to work at full speed. Cuz I did that but fan keeps same speed and pressure as always (600psi)
Correct. With signal line to solenoid disconnected the default status for the fan should be to run at max speed. I think start looking at the compensator valve on the fan pump. Is it stuck maybe..?
Tomorrow I will do some surgery to that valve and post pics. Thanks a lot Nige for all the help
Coming back with this issue. So this is the compensator valve p/n 195-9639
So I checked the compensator and its look good to me The spools move good. The help I'll need is with the regulation. When disassembling, I move the regulation bolt (below pic)
Nigel if i want this fan to run full time, but unplugging the solenoid that controls it (183-7595) makes no change what else can i do?
Start by posting a Serial Number is always a good idea.
sorry! - RTB01915 - 2005 caterpillar 938g series 2
In that case I am somewhat at a loss to explain why you are posting the question on a thread about a 140 grader. Good job i asked for a Serial Number. It may pay you to start a new thread in the wheel loader section giving all the relevant information regarding problem, symptoms, etc.
lol here let me explain it for you then. because the solenoid, and hydraulic fan control systems are almost the same? so when I do a search for that solenoid part number this thread comes up... hydraulic, electrical and mechanical system principles apply no matter the machine ....if im not mistaken his issue was that fan comes on when it shouldn't. mine wont come on when i should- but i want to manually engage it so im working backward here... AND keyword search in these forums is only so helpful...
I agree, but "almost" doesn't get you the coconut at the fair and neither does it when looking for technical information. The machine model does matter. For example I'm not going to go digging in the electrical schematic for a 140 looking for information on a 938G. I created a new thread for your problem. See HERE
Try using the search criteria below in your preferred internet browser. It works much better than the forum search. "[put your search term(s) here] site: "